Tube bending machine



Jan. 23, 1962 c. T. STREIT TUBE BENDING MACHINE.

5 Sheets-Sheet 1 Filed Dec. 10. 1959 y aw INVENTOR. Clarence 7:56:22 BYJan. 23, 1962 c. T. STRElT TUBE BENDING MACHINE 5 Sheets-Sheet 2 FiledDec. 10, 1959 INVENTOR. Clarence 7156a? 'Jan. 23, 1962 c. 'r. STRElTTUBE BENDING MACHINE 5 Sheets-Sheet 3 Filed Dec. 10, 1959 mm .mm a

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Jan. 23, 1962"- c. T. STREIT TUBE BENDING MACHINE 5 Sheets-Sheet 4 FiledDec. 10, 1959 INVENTOR. Clarence TJZrezLZ Jan. 23,1962 c. T. STREIT TUBEBENDING MACHINE 5 Sheets-Sheet 5 Filed Dec. 10, 1959 INVENTOR. Claim 65%3,017,917 TUBE BENDHNG MAC Clarence 'l. Streit, Aurora, llll., assignorto Pines Engineering (10., line, Aurora, lit, a corporation of IllinoisFiled Dec. 10, 1959, Ser. No. 858,699 7 Claims. (Cl. 153-45) The presentinvention relates to improvements in tube bending machines and isparticularly concerned with the structure and assembly of a machineadapted for righthand and left-hand bending and including positive drivemeans for the pressure die holder.

More particularly the tube bending machine herein disclosed includes abase structure upon which is mounted a top assembly including ahydraulically operated piston assembly for operating the bending formand pressure die holder which are integrally connected so as to operatein unison. The top assembly is pivotally mounted on the base structureso as to be capable of being swung through an arc of 180, thus adoptingthe machine for right-hand and left-hand bending. Toolin changeovers forrighthand and left-hand bending are maintained at a minimum by providingthe top assembly with dual sets of bending forms and clamp and pressuredie holders, one set being available for use for right-hand bending andthe other set for left-hand bending. An angle of bend selector iscontained in the top assembly and may be indexed manually'orhydraulically.

The machine herein disclosed has the advantage of being capable ofperforming right-hand and left-hand bends with minimum changeover timeand labor and is eX- tremely accurate in its bending operations owingprimarily to the positive controlled drive of its pressure die holder.Furthermore, the base structure serves as a large capacity reservoir forhydraulic fluid, thus affording long production runs at full speed.

It is therefore an object of the invention to provide a novel ruggedlyconstructed tube bending machine.

Another object is to provide a bending machine of the character hereindisclosed with a novelly mounted top assembly which may be easily andquickly swung into positions for right-hand and left-hand bendingoperations.

Another object is to provide a novelly constructed bending form andpressure die holder assembly adapted to be positively driven in unisonand hydraulically.

Another object is to provide novel hydraulic drive means for the bendingform and pressure die holder assembly.

With the foregoing and other objects in view which will appear as thedescription proceeds, the invention consists of certain novel featuresof construction, arrangement and combination of parts hereinafter fullydescribed, iliustrated in the accompanying drawings, and

particularly pointed out in the appended claims, it being understoodthat various changes in the form, proportion, size and minor details ofthe structure may be made without departing from the spirit orsacrificing any of the advantages of the invention.

For the purpose of facilitating and understanding of" spection of which,when considered in connection with the following description, theinvention, its mode of construction, assembly and operation, and many ofits advantages should be readily understood and appreciated.

Referring to the drawings in which the same char-' 3,dl7,l7 PatentedJan. 23, 1962 FIG. 2 is a top plan view thereof.

FIG. 3 is an elevational view of the front end thereof, showing the basestructure broken away.

FIG. 4 is an enlarged horizontal sectional view of the top assembly,showing parts in elevation.

FIG. 5 is a vertical longitudinal sectional view taken substantially online 5-5 of FIG. 4, showing parts in elevation.

FIG. 6 is a vertical sectional view taken substantially on line 66 ofFIG. 2.

FIG. 7 is a transverse sectional view of the top assembly, taken on line7-7 of FIG. 4.

FIG. 8 is a transverse sectional view of the top assembly, takensubstantially on line S8 of FIG. 4.

FIG. 9 is a transverse sectional view of the top assembly, taken on line9-9 of FIG. 2.

Referring to the accompanying drawings, the tube bending machinedisclosed in an exemplary form comprises essentially a base structure 11and a top assembly generally indicated at 12. The base structurepreferably is fabricated from heavy steel plate to form a rigid loadsupporting assembly, the lower portion of which comprises a reservoirfor hydraulic fluid used in the operation of hydraulic operating meansto be described presently. Mounted on one end of the base structure andin flow communication with the fluid reservoir is a pump, generallyindicated at 13 (FIG. 1) having an operating connection through a shaft14 with a suitable power source such as electric motor 15.

The top assembly 12 is in the form of a horizontally elongatedsteelplate casing 16 that is arranged in a horizontal plane above thebase structure and which extends beyond each end thereof. The topassembly is hingedly mounted on the base structure, as by means of aheavy duty hinge assembly 17 comprised of a strip 18, secured to the topwall of the base structure as by bolts or rivets 19, and havingupstanding journals 2.1, to each of which is pivotally secured, as bypivot pins 22, one of a pair of bearing lugs 23 integrally connected toone side wall 16a of casing 16.

The hinge mounting for the top assembly affords means whereby saidassembly may be swung from the position illustrated in full lines inFIGS. 2 and 3 into a position shown in broken lines in said figures. Thepurpose of such hinge mounting will become more apparent as thedescription proceeds but may be broadly stated as affording a primarystructure adapting the machine to be used for forming either right-handor lefthand bends in tubing being serviced on the machine without costlydelays for re-tooling. The top assembly 12 houses and mounts the bendingforms, the stationary clamp die holders, the swinging pressure dieholders and the drive mechanism therefor, as Well as an angle of bendselector all to be described in detail hereinafter.

The bending forms 24'are mounted at one end of the top assembly. This isbest illustrated in FIGS. 2 and 6, wherein said bending forms are shownmounted at opposite ends of a spindle assembly journalled in a nosehousing 25 fixedly secured to one end of the steel plate casing 16. Morespecifically, the nose housing comprises a hollow casting suitablyflanged at its open end, as at 26, for securement to said casing andprovided with vertically aligned anti-friction bearings 27 in its topand bottom walls to provide journals for hub portions 28 projecting oneon each side of a sprocket 29. Each of the hub portions 28 have endextensions 31 of reduced" diameter each mounting a non-circular mountingmember 32 having studs 3334 (FIG. 2) extending outwardly thereof toreceive the bending forms 24. Set screws 35 (only one shown in FIG. 6)secure the mounting members to the respective hub portions 28 forrotation therewith. In the present disclosure the axial studs 33 areconnected by an axial tie rod 36.

A forked arm 37 is fitted over hubs 28 in embracing relationship tosprocket 29 and is secured thereto for rotation with the sprocket by oneor more threaded pins 38. The arm 37 projects outwardly radially througha slot 39 in the side wall of nose housing 25 and is secured firmly, asby bolts or rivets 41 to one end of a vertically disposed swing plate 42having upper and lower guide flanges 43 on its horizontally disposedlongitudinal edges. As best shown in FIG. 6, the guide flanges 4-3 arecomprised of heavy strips that are welded or otherwise securedintegrally to said plate and they extend inwardly beyond the inner edgethereof and are in tight endwise abutment with the related side face ofthe respective mounting members 32. The structure, insofar as it isdescribed, affords a firm mounting for swing plate 42 and assures thatit will at all times rotate about the axis of sprocket 29 and bendingforms 24 when the latter are rotated in a manner to be describedpresently. This assembly is adapted to mount one or two pressure dieholders to be described presently.

A similarly constructed but rigidly mounted plate 45 including upper andlower guide flanges 46 is mounted directly on the nose housinglongitudinally inwardly of the axis of bending forms 24 and extendsperpendicular to the longitudinal axis of the top assembly as best shownin FIG. 2. This plate assembly is adapted to mount one or two stationaryclamp die holders. The pressure die holders and the stationary clamp dieholders are alike in their construction and operation and the followingdescription of one will be fully applicable to the other and likenumerals are used to identify corresponding parts.

Referring specifically to the disclosure of the pair of pressure dieholders best illustrated in FIG. 6, it will be observed that one isshown mounted on the upper guide flange 43 and the other is mounted onthe lower guide flange 43. Each holder comprises an assembly including atoggle casting 47 slidable on flange 43 but adapt-ed to be fixedlysecured in a position of longitudinal adjustment therealong as by meansof a lick screw 48. A backup plate 49 is arranged on flange 43 betweenthe rear edge of said toggle casting and an adjustment screw 51 carriedby a vertically extending end plate 52 secured to the free or rear endof swing plate 42. Upon loosening screw 48 and adjusting screw 51, thetoggle casting 47 can be moved into any required position of adjustmentalong flange 43.

A toggle link 53 is pivotally connected, at 54, to toggle casting 47 andis connected by a chain link 55 to a slide casting 56 also guided onflange 43. The slide casting on the pressure die holder assembly isadapted to have removably mounted thereon, pressure die 57 which has itsface opposed to bending form 24 provided with a semicircular recess 58that is complemental to the perimeter recess 59 in said bending form. Inthe instance of the stationary clamp die holder assembly, the slidecasting 56 receives and mounts a clamp die 57a which is structurallysimilar to the pressure die 57.

The function and operation of the pressure die holder and stationaryclamp die holder and the dies mounted therein will be explained indetail presently but it should be noted at this time that the provisionof a pair of dies one on each edge of the respective holder assembliesaffords means whereby the top assembly 12 may be positioned on the baseassembly for immediate operation to effect right-hand or left-handbending. In the drawings, the top assembly is shown in full lines in theposition assumed for making left-hand bends. In order to make right-handbends, the top assembly is swung 180 about its pivotal mounting 17 fromsaid full line position into a position fully overlying base structure11, substantially as shown in broken lines in FIGS. 2 and 3. Suchrepositioning of the top assembly reverses the positions of thestationary clamp die holders and the swinging pressure die holders andmakes the bending form and dies previously disposed on the bottom sideof the nose assembly available for use on the upper side thereof.

In use, while in either of its positions, a tube or rod 61 to be bent,is laid over the upper face of the top assembly with its rearmost endheld by a conventional holder assembly (not shown) and its forward endextended beyond and clamped firmly between the stationary clamp die 57aand the bending form 24. Power is applied, in a manner to be describedpresently, for rotating the bending form and the swinging pressure dieholder in unison to effect the desired bending of forward end portion ofthe tube.

As earlier indicated herein, hydraulic fluid supplied by operation ofpump 13, provides the motivating power for rotating the spindleassembly. This means, best shown in FIGS. 4 and 5, includes a cylinder62 mounted in a horizontal plane on a platform 63 secured to the insideface of the bottom wall 16b of the steel plate casing 16. A piston 64 isoperable within said cylinder which has hydraulic lines 65-66 one inflow communication with each end thereof and connected to pump 13. Asuitable three-way valve (not shown) is provided in said lines which isunder control of the operator for admitting fluid to either end of saidcylinder so as to drive the piston in either direction therein. A pistonrod 67, connected to said piston, extend through a packing gland 68 onthe rear end of said cylinder and carries a cross-head 69 having aconnecting lug 71 integral therewith. A length of sprocket chain 72 orother flexible medium, is connected at one of its ends to saidconnecting lug 71 as by a pin 73. This chain is trained around an idlersprocket 74 journalled in bearing plates 75 (FIG. 9) secured firmly toand within the steel plate casing 16, and its other end is connected, asat 76, to one end of a tie bar 77 extending longitudinally within saidcasing.

Tie bar 77 is of such length as to terminate short of nose housing 25and its forward end is connected, as at 78, to one end of a secondlength of sprocket chain 79 that is trained around spindle sprocket 29and has its other end connected by a pin 81 to a cross-head 82. Rods 33rigidly connect cross-head 82 to the piston rod cross-head 69, said rodsextending through apertures therein and being secured thereto firmly, asby means of lock nuts 84 and 85 respectively.

The rods 83 are guided for longitudinal reciprocation in an upstandingwall 86 secured at its lower margin to the forward end of platform 63 asby screws 87. In operation, any longitudinal movement imparted to piston64 by selective operation of the hydraulic control valve is transmittedto the sprocket chain and bar assembly for rotating spindle sprocket 29and rotating the bending form and pressure die holder assembly.

In order to control the angle of bend obtained by operation of thebending form and pressure die, and particularly the angle of each bendwhen successive bends are made in a length of tubing, the machine isprovided with an angle of bend selector 88, best shown in FIGS. 4, 5 and7. This selector comprises a turret or indexing cylinder 89 journalledfor free rotation on one of the rods 83. Preferably, it includes abearing sleeve 91 fitted over said rod and journalled also in theupstanding wall 86. If desired, said sleeve may have on its rearwardlyextending end, a ratchet 92 adapted, for use in automatic indexing ofthe turret. In such instance hydraulic means, not shown, may beassociated with the ratchet 92 for incremental rotation thereof.Specifically, turret 89 has a plurality of circumferentially spaced stoprods 93 mounted securely therein and each projecting forwardlytherefrom. Rods 93 are of lengths each representing the amount ofrotation of the pressure die holder and bending form assembly requiredto obtain the desired amount of bending in the tube during each bendingoperation.

The rods 93 are positioned, selectively or automatically, by rotation ofthe turret for in-line abutment by a stop boss 94 carried on therearwardly disposed face of cross-head 82. Otherwise stated, the turretmay be positioned to locate any one of its stop rods 93 in axialalignment with stop boss 94. When the machine is operated to form a bendin the tube, it will continue the bending operation until stop boss 94strikes the end of the aligned rod 93. This holds the piston againstfurther movement under its hydraulically applied power whereupon theoperator will release the clamping and pressure dies 57a and 57respectively, and then reverse the hydraulic flow valve to return thebending form and pressure die holder to their initial or at restpositions. The tube being formed is then advanced into the next bendposition, the clamp and pressure dies reset and the turret indexed,manually or automatically, to locate the required rod 93 in position forabutment by stop boss 94 during the next bending operation. Accurateindexing of the turret is assured by providing the indexing cylinder 89with a recess 95 for cooperative engagement by an indexing ball 96carried by wall 86. This ball preferably is urged into such engagementby a spring 97 carried in the ball containing recess 98. Variation inthe effective tension of said spring may be obtained by adjustment of aset screw 99. This sequence is repeated for each bend to be made in thetube and should the machine be positioned at any time to make right-handbends, the top assembly 12 may be swung over easily and quickly aboutits hinge mounting 17 to adapt it for making any required left-hand bendwithout materially slowing down bending operations; it being necessaryonly to reposition the tube on the then top side of the top assembly andengage it in the uppermost bending form and die assembly.

It is believed that the invention, its mode of construction andassembly, and many of its advantages should be readily understood fromthe foregoing without further description; and it should also bemanifest that, while preferred embodiments of the invention has beenshown and described for illustrative purposes, the structural detailsare nevertheless capable of wide variation within the purview of theinvention as defined in the appended claims.

What I claim and desire to secure by Letters Patent of the United Statesis:

1. In a tube bending machine including a base structure and a topassembly, said assembly comprising an elongated casing having a pair ofbending forms, clamp die holders and pressure die holders operablyassociated therewith, and hinge means connecting the top assembly to thebase structure adapting the former to be swung into positions permittinguse of one or the other of said pair of bending forms, clamp die holdersand pressure die holders.

2. The tube bending machine of claim 1, in which the hinge means is of acharacter that permits the top assembly to be swung 180 on an axisparallel to its longitudinal axis.

3. The tube bending machine of claim 1, in which the hinge meanscomprises a hinge element mounted on the top surface of the basestructure and complemental hinge elements carried on one longitudinalside wall of said elongated casing.

4. In atube bending machine including a base structure having ahydraulic fluid reservoir therein, a top assembly mounted on said basestructure, a hydraulic piston-cylinder assembly mounted in said topassembly, a bending form spindle assembly including a sprocket mountedon one end of said top assembly, an idler sprocket mounted adjacent tothe other end of said top assembly, an endless chain assembly trainedover said sprockets and connected to the piston for rotating thesprockets and spindle assembly when the piston is operated, means todeliver fluid from the reservoir to said piston-cylinder for operatingthe piston, a pair of bending forms mounted on each end of the spindleassembly, a stationary arm secured firmly to the top assembly, a pair ofclamp dies carried by the stationary arm one for cooperative associationwith each bending form, a swinging arm connected firmly to the spindleassembly and movable therewith, a pair of pressure dies carried by theswinging arm one for cooperative association with each bending form, andmeans mounting the top assembly on the base structure to permit it to beswung through an arc of so as to enable use of either one of the bendingforms and the clamp and pressure dies associated therewith.

5. In a tube bending machine, a housing including top and bottom wallsand a substantially circular side wall connecting said top and bottomwalls, a spindle journalled in the top and bottom walls and extendingoutwardly therefrom, a bending form secured to one end of said spindle,a sprocket on said spindle and within said housing, said housing sidewall having a circumferential opening therein, and a pressure die holdersecured firmly to said sprocket and extending outwardly radially throughsaid opening.

6. The tube bending machine of claim 5, in which the pressure die holderhas a pressure die thereon for cooperation with the bending form duringa tube bending operation.

7. The tube bending machine of claim 5, in which a bending form issecured to each end of said spindle and the pressure die holder haspressure dies mounted thereon one for cooperation with each bendingform.

References Cited in the tile of this patent UNITED STATES PATENTS404,012 Nickerson May 28, 1889 1,545,164 Norton July 7, 1925 2,022,912Heineman Dec. 3, 1935 2,143,443 Kelso Jan. 10, 1939 2,488,896 Bertoliniet al. Nov. 22, 1949 2,614,605 Senna Oct. 21, 1952 2,655,193 Payne Oct.13, 1953 2,672,224 Horwitz Mar. 16, 1954 2,810,422 Bower Oct. 22, 19572,871,909 Bower Feb- 3, 1959 FOREIGN PATENTS 155,378 Australia Feb. 23,1954

